CURRENT Essentials of Critical Care.pdf

Chapter 2 ICU Supportive Care for Specific Medical Problems 27■■Pregnant PatientsEssential Concepts• Altered maternal physiology, presence of fetus, diseases specificto pregnancy make management challenging• Organ systems adapt to optimize fetal and maternal outcome• Cardiovascular system: electrical axis changes with lateral deviationof apex; cardiac output, heart rate, stroke volume increase;reduced peripheral vascular resistance leads to decreasedsystemic blood pressure• Respiratory system: minute ventilation increases in excess ofneed for oxygen delivery; “hyperventilation of pregnancy” hormonallymediated and results in decreased PaCO 2 (28 to 32 mmHg); compensatory bicarbonate loss maintains normal pH• Hematologic system: disproportionate plasma volume increasecompared to red cell mass leads to “dilutional anemia”; increasedthromboembolic risk due to alterations in clotting factors,venous stasis, vessel wall injury• Laboratory changes: creatinine decreases while creatinine clearanceincreases; elevated alkaline phosphatase related to placentalproductionEssentials of Management• Position: avoid supine position after 20 weeks gestation; rightlateral decubitus or Fowler position (head of bed elevated) preferredfor immobilized patient• Monitoring: fetal heart tones should be part of vital signs; continuousfetal monitoring after 23 weeks’ gestation if maternalcondition affects cardiopulmonary function• Thromboembolism prophylaxis: unfractionated or low molecularweight heparin if not contraindicated; venous compressionstockings of lesser benefit• Nutrition: address early as pregnant women more susceptible tostarvation ketosis• Imaging studies: ionizing radiation known to be teratogenic;limit radiographs appropriately but do not withhold if resultsmay lead to therapeutic intervention■ PearlAlthough care of the mother is the primary concern in most circumstances,attention must also be paid to fetal health and well-being.ReferenceNaylor DF et al: Critical care obstetrics and gynecology. Crit Care Clin2003;19:127. [PMID: 12688581]